Pope Francis touches the stones of the Western Wall, Judaism's holiest prayer site, in Jerusalem's Old City May 26, 2014. Francis completes a tour of the Holy Land on Monday, paying homage to Jews killed in the Nazi Holocaust and looking to affirm Christian rights at a disputed place of worship in Jerusalem.

At a ceremony attended by Israeli President Shimon Peres and Palestinian President Mahmoud Abbas in the Vatican Gardens at the Vatican on Sunday evening, Pope Francis said God alone can bring peace to the Holy Land and that it is the "evil one" who is blocking it.

"More than once we have been on the verge of peace, but the evil one, employing a variety of means, has succeeded in blocking it," the pope said Sunday at an evening ceremony, according to Catholic News Service. "That is why we are here, because we know and we believe that we need the help of God."

"Peacemaking calls for courage, much more so than warfare. It calls for the courage to say yes to encounter and no to conflict; yes to dialogue and no to violence; yes to negotiations and no to hostilities," Francis added, according to Reuters.

The pope stressed that peace requires respect for agreements and rejection of acts of provocation. "All of this takes courage, it takes strength and tenacity," he said.

"We have heard a summons and we must respond. It is the summons to break the spiral of hatred and violence, and to break it by one word alone: the word 'brother,'" Francis added.

The pontiff also said the importance of peace can be seen in light of innocent victims of wars and conflict, including children. "The memory of these children instills in us the courage of peace, the strength to persevere undaunted in dialogue."

Francis invited the two leaders during his first visit as pope to the Holy Land last month. The two presidents met for the first time at a public meeting on Sunday in more than a year.

"I was young, now I am old. I experienced war, I tasted peace," Peres was quoted as saying in a statement. "Never will I forget the bereaved families, parents and children, who paid the cost of war. And all my life I shall never stop to act for peace for the generations to come. Let's all of us join hands and make it happen."

"We want peace for us and for our neighbors," Abbas was quoted as saying. "We seek prosperity and peace of mind for ourselves and for others alike."

During his trip to the Holy Land, the pope spoke in favor of the rights of Palestinians to a sovereign homeland as well as Israel's right to exist in peace.

While the official purpose of the pope's visit was to improve ties with the Orthodox Church, Francis was believed to have four goals, including to bring about peace in the Middle East, especially a resolution of the Palestinian-Israeli conflict.

Also present at the Sunday's ceremony at the Vatican was Ecumenical Patriarch Bartholomew of Constantinople, who read from the Book of Isaiah: "The wolf and the lamb shall feed together; the lion shall eat straw like the ox; but the serpent – its food shall be dust."

At the end of the ceremony, the pope, the patriarch and the two presidents kissed each other on both cheeks. They also spoke privately later.